My understanding is that pthread_cond_wait is a cancellation point. It achieves this by entering asynchronous cancellation mode before blocking.
I don't see, however, any code that checks for a pending cancellation when we enter the function. As far as I can tell, the implementation is that pthread_cond_wait is a cancellation point if and only if the thread is canceled while it is blocked. Right now, I can't think of any solution involving checking for cancellation that doesn't include a potential gap between checking for cancellation and entering asynchronous cancellation mode. Anyway, I meant this as informative. Thomas D. PS Non-informative: setcanceltype in the cleanup function appears to be in the wrong place. Shouldn't it be the first thing to happen? Spin lock and spin unlock aren't async-cancel-safe, right? So, if we are in cleanup, lock the lock, and someone cancels us: async-cancellation injects a call to pthread_exit, where we call cleanup again and deadlock trying to lock a lock we hold.
